As you can see, the operating system technology has evolvedand is continuing to evolve. It seems like Microsoft is always comingout with a new and better operating system which leads people towonder whether or not the system they are currently using is reallythe best one.It can be confusing. But it doesn’t have to be. In the pages ofthis book, we’ll explore operating system in depth. Yothey do, how they work, and what needs specific systems canmeet. Ultimately, the choice is a matter of preference, but it helps tobe informed on what you are really getting when choosing an OS.We’ll show you operating systems uncovered, so read on!Table of ContentsIntroduction 3What is an Operating System 4History of Operating Systems 6What an Operating System Does 8Process Management 9Memory Management 13Disk and File Systems 16Networking 16Security 16Internal Security 18External Security 18Graphical User Interface 19Device Drivers 19Application Interface 20Microsoft Windows 22Mac OS 29UNIX 33Linux 35GNU 37Other Operating Systems 38Installing an Operating System 39Defining the Processes 43Cache 43Virtual Memory 48System Resources 50RAM 51Computer Memory 55Conclusion 60